1 files changed, 75 insertions, 0 deletions
diff --git a/numpy/core/_methods.py b/numpy/core/_methods.py
index 3ab64f7a1..ba6f7d111 100644
--- a/numpy/core/_methods.py
+++ b/numpy/core/_methods.py
@@ -11,6 +11,7 @@ from numpy.core import multiarray as mu
 from numpy.core import umath as um
 from numpy.core._asarray import asanyarray
 from numpy.core import numerictypes as nt
+from numpy.core import _exceptions
 from numpy._globals import _NoValue
 
 # save those O(100) nanoseconds!
@@ -55,6 +56,80 @@ def _count_reduce_items(arr, axis):
         items *= arr.shape[ax]
     return items
 
+# Numpy 1.17.0, 2019-02-24
+# Various clip behavior deprecations, marked with _clip_dep as a prefix.
+
+def _clip_dep_is_scalar_nan(a):
+    # guarded to protect circular imports
+    from numpy.core.fromnumeric import ndim
+    if ndim(a) != 0:
+        return False
+    try:
+        return um.isnan(a)
+    except TypeError:
+        return False
+
+def _clip_dep_is_byte_swapped(a):
+    if isinstance(a, mu.ndarray):
+        return not a.dtype.isnative
+    return False
+
+def _clip_dep_invoke_with_casting(ufunc, *args, out=None, casting=None, **kwargs):
+    # normal path
+    if casting is not None:
+        return ufunc(*args, out=out, casting=casting, **kwargs)
+
+    # try to deal with broken casting rules
+    try:
+        return ufunc(*args, out=out, **kwargs)
+    except _exceptions._UFuncOutputCastingError as e:
+        # Numpy 1.17.0, 2019-02-24
+        warnings.warn(
+            "Converting the output of clip from {!r} to {!r} is deprecated. "
+            "Pass `casting=\"unsafe\"` explicitly to silence this warning, or "
+            "correct the type of the variables.".format(e.from_, e.to),
+            DeprecationWarning,
+            stacklevel=2
+        )
+        return ufunc(*args, out=out, casting="unsafe", **kwargs)
+
+def _clip(a, min=None, max=None, out=None, *, casting=None, **kwargs):
+    if min is None and max is None:
+        raise ValueError("One of max or min must be given")
+
+    # Numpy 1.17.0, 2019-02-24
+    # This deprecation probably incurs a substantial slowdown for small arrays,
+    # it will be good to get rid of it.
+    if not _clip_dep_is_byte_swapped(a) and not _clip_dep_is_byte_swapped(out):
+        using_deprecated_nan = False
+        if _clip_dep_is_scalar_nan(min):
+            min = -float('inf')
+            using_deprecated_nan = True
+        if _clip_dep_is_scalar_nan(max):
+            max = float('inf')
+            using_deprecated_nan = True
+        if using_deprecated_nan:
+            warnings.warn(
+                "Passing `np.nan` to mean no clipping in np.clip has always "
+                "been unreliable, and is now deprecated. "
+                "In future, this will always return nan, like it already does "
+                "when min or max are arrays that contain nan. "
+                "To skip a bound, pass either None or an np.inf of an "
+                "appropriate sign.",
+                DeprecationWarning,
+                stacklevel=2
+            )
+
+    if min is None:
+        return _clip_dep_invoke_with_casting(
+            um.minimum, a, max, out=out, casting=casting, **kwargs)
+    elif max is None:
+        return _clip_dep_invoke_with_casting(
+            um.maximum, a, min, out=out, casting=casting, **kwargs)
+    else:
+        return _clip_dep_invoke_with_casting(
+            um.clip, a, min, max, out=out, casting=casting, **kwargs)
+
 def _mean(a, axis=None, dtype=None, out=None, keepdims=False):
     arr = asanyarray(a)